Yeah, you have the option of when to start.
~You can start on a Sunday. There's nothing special about sunday, it just is easy to remember and lowers your chance of getting your period on a weekend. If you do this, you have to wait a week before you can have unprotected sex. And yes, you must start at the beginning of the pack, not the dummy pills. That would do nothing.
~You can start on the first day of your period. In that case, you would take the first real active pill and you could have unprotected (no condom) sex right away.
~Or you could start any darn day you choose- just take the first active pill in the pack and wait a week before you have unprotected sex.
If your pill pack is labeled with the days of the week, then often times it comes with day of the week stickers so you can put them over the printed ones (and therefore always know what day you are on so you don't get messed up) or you could just write over it.
Your doctor should've told you this!!!